Levels of Organization, Perspectives, and Causal Thickets* (Canadian Journal of Philosophy, Supp
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THE ONTOLOGY OF COMPLEX SYSTEMS: Levels of Organization, Perspectives, and Causal Thickets* (Canadian Journal of Philosophy, supp. vol #20, 1994, ed. Mohan Matthen and Robert Ware, University of Calgary Press, 207-274). by William C. Wimsatt Department of Philosophy University of Chicago January 4, 1994 [email protected] [REVISED MINIMALLY FOR THE COLLECTION] Willard van Orman Quine once said that he had a preference for a desert ontology. This was in an earlier day when concerns with logical structure and ontological simplicity reigned supreme. Ontological genocide was practiced upon whole classes of upper-level or "derivative" entities in the name of elegance, and we were secure in the belief that one strayed irremediably into the realm of conceptual confusion and possible error the further one got from ontic fundamentalism. In those days, one paid more attention to generic worries about possible errors (motivated by our common training in philosophical scepticism) than to actual errors derived from distancing oneself too far from the nitty-gritty details of actual theory, actual inferences from actual data, the actual conditions under which we posited and detected entities, calibrated and "burned in" instruments, identified and rejected artifacts, debugged programs and procedures, explained the mechanisms behind regularities, judged correlations to be spurious, and in general, the real complexities and richness of actual scientific practice. The belief that logic and philosophy were prior to any possible science has had a number of distorting effects on philosophy of science. One of these was that for ontology, we seemed never to be able to reject the null hypothesis: "Don't multiply entities beyond necessity." But Ockham's razor (or was it Ockham's eraser?) has a curiously ambiguous form--an escape clause which can turn it into a safety razor: How do we determine what is necessary? With the right standards, one could remain an Ockhamite while recognizing a world which has the rich multi-layered and interdependent ontology of the tropical rain forest--that is, our world. It is tempting to believe that recognizing such a world view requires adopting lax or sloppy standards--for it has a lot more in it than Ockhamites traditionally would countenance. Quite to the contrary, I think that the standards for this transformation are not lax, but only different. Indeed, the standards which I urge are closer to our experience and arguably more fundamental than those used during the hegemony of foundationalist methods and values. In the first section, I will discuss this criterion for what is real--what I call robustness--a criterion which applies most simply and directly, though not exclusively, to objects. In subsequent sections, I will use robustness and other information about our world to delineate the major structural features--primarily levels, but with some comments on what I call 'perspectives' and 'causal thickets'--which dominate our world, our theories, and the language we use to talk about both. These are higher-level ontological features, Organizational Baupläne, related to the things that people usually talk about under the topic of ontology (things like objects, properties, events, capacities, and propensities) as paragraphs are to words and phonemes or morphemes. But they are there nonetheless--it is only our concern with the little things, motivated by foundationalist or reductionist concerns-- which has deflected our attention from them. This ontology--of levels, perspectives, and causal thickets--is no less required for a full accounting of the phenomena of the physical sciences than it is for biology and the social sciences, but its obdurate necessity has seemed more obvious in these latter cases. This may now be changing. The increased interest in fractal phenomena and chaotic and, more generally, non-linear dynamics emerging from the so- called "exact sciences" has brought many noisy residua of the ontological scrap-heaps of the physical sciences to the center of attention as theoretically revealing data, structures, and objects with new-found status. Most of these things have never before made it into theory--or if so, only into the "theory of observation" under the topic of "error analysis" where they lived in the ubiquitous error term. Messiness--or at least the right kinds of messiness--is now almost a virtue in many of the sciences, as the recent explosion of interest in complexity seems to attest1. Levels, * I would like to thank Irene Appelbaum, Bill Bechtel, Chuck Dyke, Stuart Glennan, Sergio Martinez, Alirio Rosales, Jeff Schank, Bob Ware, and Barbara Wimsatt for discussion and useful commentary on matters both substantial and stylistic, Sylvia Culp for very useful last minute input, and Bob Ware for his tolerance as an editor. 1 For a philosophical response to “the new messiness”, see for example John Dupre’s provocative new book, The Disorder of Things (Dupre, 1993). But while Dupre and I both urge major surgery on our ontologies, methodologies, and epistemological assumptions, and make movements in many of the same directions, I believe that my surgery is ultimately more conservative (particularly in defending a liberalized (and non-eliminative) descendant of classical mechanistic materialism, and is also more in accord with actual scientific practice. (Our differences on the former but I think not on the latter point may be in part ideological or rhetorical rather than substantive.) Dupre could urge in return that I haven’t paid sufficient attention to the social determinants and aspects of our practice. To this I plead guilty, though I think the view argued here can both deal with and in part explain those complexities. Wimsatt: Levels, Perspectives, Causal Thickets page 2 September 23, 2003 10:02 AM perspectives, and causal thickets are major ontological players in these complex areas--domains with significant implications for how to approach many of philosophy's most refractory problems. Because the aim of this paper is ultimately taxonomic--to say what there is, or to describe some of the bigger things that are--the descriptive sections will basically take the form of a list of properties, elaborated either to explain ideas likely to be unfamiliar further, or to explain relations among the properties which help to give the ideas of level and perspective their cohesiveness. Taxonomy may sound boring, but I hope to show you that the description of and relations between a family of newly discovered species can be an exciting task. I. ROBUSTNESS AND REALITY: Before I say what there is in this complex world, I should give my criteria for regarding something as real or trustworthy. Particularly among those of a foundationalist persuasion, it is common to start by providing some criterion, be it indubitability, incorrigibility, or other means of picking out things or assumptions whose veracity is not open to question. One then says that those things are real (true, indubitable, or whatever) if it is either one of these primitive things or if it is derivable from them via a valid series of inferences. Only things admitted in one of these two ways are allowed. I share the foundationalist's concern with securing reliability for our conceptual structures. But I don't think that there are any criteria which both give indubitability or render error impossible, and permit any interesting inferences from that starting point. Thus, I would rather give a criterion which offers relative reliability, one that you're better off using than not, indeed better off using it than any other, and which seems to have a number of the right properties to build upon. Rather than opting for a global or metaphysical realism (an aim which bedevils most of the analyses of "scientific realists"), I want criteria for what is real which are decidedly local--which are the kinds of criteria used by working scientists in deciding whether results are "real" or artifactual, trustworthy or untrustworthy, "objective" or "subjective" (in contexts where the latter is legitimately criticized-- which is not everywhere). When this criterion is used, eliminative reductionism is seen as generally unsound, and entities at a variety of levels--as well as the levels themselves--can be recognized for the real objects they are, and traditional foundationalism and ontic fundamentalism are in trouble. They will survive, if at all, as a local kind of problem-solving technique of significant but limited usefulness. [But see the last essay on dynamical foundationalism.] Following Levins (1966), I call this criterion robustness. (See Wimsatt, 1981a, for an analysis and review of the concept and methodology, 1980a, 1980b, for relevant case studies, Campbell, 1966, whose concept of "triangulation" captures many of the same ideas, and whose classic work with Fiske (1959) on the "multi-trait-multi- method matrix" brought this methodology to the social sciences). Things are robust if they are accessible (detectable, measureable, derivable, defineable, produceable, or the like) in a variety of independent ways. A related but narrower criterion (experimental manipulability via different means) has since been suggested by Hacking (1983), who draws a close link with experiment, and limits his discussions to the realism of entities. But robustness plays a similar role also in the judgement of properties, relations, and even propositions, as well as for the larger structures--levels and perspectives--described below (see Wimsatt, 1981a, and also 1974, 1976a). Furthermore, the independent means of access are not limited to experimental manipulations but can range all the way from non-interventive observation or measurement to mathematical or logical derivation, with many stops in between. Experimental manipulation is just a special case. We feel more confident of objects, properties, relationships, etc. which we can detect, derive, measure, or observe in a variety of independent ways because the chance that we could be simultaneously wrong in each of these ways declines with the number of independent checks we have.2 We can only make the probability of failure decline--though it can get very small, it does not go to zero.